Dissident republicans who bombed a police station near the border are hell-bent on killing police officers, it was claimed today.

Just hours after security chiefs warned that the terrorist threat level in the North was as high as any time since the Omagh atrocity 12 years ago, the station at Newtownhamilton, in south Armagh, was blasted.

Fire officers who managed to evacuate families from nearby homes just minutes before the car bomb exploded - damaging shops, a community centre and houses - were hailed heroes and a police commander in the area claimed the terrorists were intent on causing bloodshed.

Chief Inspector Sam Cordner, who defended his men against allegations that they were slow to respond to the latest attack, said: "These people are hell-bent on killing police officers in the area."

Two people, one an elderly woman, were slightly hurt in the explosion late last night and the attack confirmed heightening fears that dissidents will step up their campaign in the run-up to the General Election.

The North's First Minister Peter Robinson and new Justice Minister David Ford condemned the bombers, who fired shots into the air as they abandoned the car bomb outside the station.

It was the second time in a week that the base has been targeted. A previous car bomb failed to go off.

The station was unoccupied at the time and police were on their way to the town when the bomb exploded.

Fire service personnel were already at the scene and helped take local people to safety before the explosion.

Assembly member Danny Kennedy contrasted the response of the two services.

"The police were still not present at that time (when the bomb exploded) and had it not been for the excellent and very prompt work of local firemen, then we could have had a very serious situation," said the Ulster Unionist.

"Clearly those (police) response times are not appropriate, they are not in line with responses that should be given, given the overall security situation."

Evacuated residents were taken to nearby Newtownhamilton High School.

The attack, which damaged a number of homes, a pub and a community centre, happened 10 days after a device inside a vehicle was defused outside the station.

That incident came 24 hours after a Real IRA car bomb exploded outside the regional headquarters of MI5 in Holywood, Co Down, minutes after justice powers were devolved to Stormont from London.

Mr Ford said the latest bombing was not just an attack on the people of Newtownhamilton but on the wider political process.

"With the progress that has been made in Northern Ireland, people will be asking who are dissident republicans fighting now?" he said.

"Are they fighting the notion of self-government on a scale never seen before in Northern Ireland?

"Are they fighting representatives from across this community who form the Northern Ireland Executive or are they fighting the people from all parts of the community who make up the police service?

"Those who planted this bomb want to drag Northern Ireland back to the dark days of murder and mayhem, they want to undermine the political process, they want politics to fail. I am determined that we will all continue to stand together so that they will not succeed."

Newry and Armagh Sinn Fein MP Conor Murphy said: "There is little doubt that this bomb is the work of one of the small militarist factions. These people are opposed to the peace process and have no strategy to bring about political change or deliver Irish unity.

"This bomb sends a message that the peace process needs to be defended."

In a separate incident last night, a pipe bomb exploded behind a house in the Chestnut Hill area of Brackaville, Coalisland, Co Tyrone, at around 11.30pm.

A man and a woman who were in the house at the time were not injured, but a number of windows were damaged.

Security minister Paul Goggins said the explosion would only reinforce the commitment of all democrats to stand with the people against terrorism.

He added: "The Government will never be deflected from continuing to do all in its power to support the police and the devolved administration in Northern Ireland against those who attack the community and who want to destroy all that has been so hard won over the years. They will not undermine a peace process and a political process that has the overwhelming support of democrats around the world."